ScrollPattern.SetScrollPercent(Double, Double) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Sets the horizontal and/or vertical scroll position as a percentage of the total content area within the AutomationElement.
public:
void SetScrollPercent(double horizontalPercent, double verticalPercent);
public void SetScrollPercent (double horizontalPercent, double verticalPercent);
member this.SetScrollPercent : double * double -> unit
Public Sub SetScrollPercent (horizontalPercent As Double, verticalPercent As Double)
Parameters
- horizontalPercent
- Double
The percentage of the total horizontal content area. NoScroll should be passed in if the control cannot be scrolled in this direction.
- verticalPercent
- Double
The percentage of the total vertical content area. NoScroll should be passed in if the control cannot be scrolled in this direction.
Exceptions
A value that cannot be converted to a double is passed in.
A value greater than 100 or less than 0 is passed in (except -1, which is equivalent to NoScroll). The HorizontalScrollPercent and VerticalScrollPercent values are normalized to either 0% or 100%.
An attempt is made to scroll in an unsupported direction.
Examples
In the following example, a ScrollPattern control pattern is obtained from an AutomationElement and is then used to scroll the viewable region to the top left 'home' position of the content area.
///--------------------------------------------------------------------
/// <summary>
/// Obtains a ScrollPattern control pattern from an
/// automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A ScrollPattern object.
/// </returns>
///--------------------------------------------------------------------
private ScrollPattern GetScrollPattern(
AutomationElement targetControl)
{
ScrollPattern scrollPattern = null;
try
{
scrollPattern =
targetControl.GetCurrentPattern(
ScrollPattern.Pattern)
as ScrollPattern;
}
// Object doesn't support the ScrollPattern control pattern
catch (InvalidOperationException)
{
return null;
}
return scrollPattern;
}
'''--------------------------------------------------------------------
''' <summary>
''' Obtains a ScrollPattern control pattern from an
''' automation element.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <returns>
''' A ScrollPattern object.
''' </returns>
'''--------------------------------------------------------------------
Private Function GetScrollPattern( _
ByVal targetControl As AutomationElement) As ScrollPattern
Dim scrollPattern As ScrollPattern = Nothing
Try
scrollPattern = DirectCast( _
targetControl.GetCurrentPattern(scrollPattern.Pattern), _
ScrollPattern)
Catch
' Object doesn't support the ScrollPattern control pattern
Return Nothing
End Try
Return scrollPattern
End Function 'GetScrollPattern
///--------------------------------------------------------------------
/// <summary>
/// Obtains a ScrollPattern control pattern from an automation
/// element and attempts to scroll to the 'home' position.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
///--------------------------------------------------------------------
private void ScrollHome(AutomationElement targetControl)
{
if (targetControl == null)
{
throw new ArgumentNullException(
"AutomationElement argument cannot be null.");
}
ScrollPattern scrollPattern = GetScrollPattern(targetControl);
if (scrollPattern == null)
{
return;
}
try
{
scrollPattern.SetScrollPercent(0, 0);
}
catch (InvalidOperationException)
{
// Control not able to scroll in the direction requested;
// when scrollable property of that direction is False
// TO DO: error handling.
}
catch (ArgumentOutOfRangeException)
{
// A value greater than 100 or less than 0 is passed in
// (except -1 which is equivalent to NoScroll).
// TO DO: error handling.
}
}
'''--------------------------------------------------------------------
''' <summary>
''' Obtains a ScrollPattern control pattern from an automation
''' element and attempts to scroll to the top left 'home' position.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
'''--------------------------------------------------------------------
Private Sub ScrollHome(ByVal targetControl As AutomationElement)
If targetControl Is Nothing Then
Throw New ArgumentNullException( _
"AutomationElement argument cannot be null.")
End If
Dim scrollPattern As ScrollPattern = _
GetScrollPattern(targetControl)
If scrollPattern Is Nothing Then
Return
End If
Try
scrollPattern.SetScrollPercent(0, 0)
Catch exc As InvalidOperationException
' Control not able to scroll in the direction requested;
' when scrollable property of that direction is False
' TO DO: error handling.
Catch exc As ArgumentOutOfRangeException
' A value greater than 100 or less than 0 is passed in
' (except -1 which is equivalent to NoScroll).
' TO DO: error handling.
End Try
End Sub
Remarks
This method is only useful when the content area of the control is larger than the visible region.
Passing in the value NoScroll indicates that there is no scrolling in the specified direction.